The present invention relates to a lidding film, without metal foil, for push-through forms of packaging and a use for the said lidding film.
It is known to cover push-through forms of packaging, so called blister packs, with a layer that covers, and is sealed onto, the whole surface area and serves as the lid for the blister pack. The blister pack features one or more individual recesses each of which holds for example solid bodies, shaped solid preparations or pharmaceutical products such as tablets or dragees. If one single item, e.g. a tablet has to be removed from a blister pack the bottom part is pressed and the tablet pushed through the covering layer acting as a lid over the recess. As a tale the material of the covering layer is of aluminium foil or a laminate of which aluminium is a component part. Aluminium foil is a preferred material for the lidding layer on blister packs as relatively little force is required to break the foil at the thickness chosen for this purpose, the energy required for this is small and the aluminium exhibits essentially no elasticity. As a rule the bottom part of the blister pack is of plastic such as, e.g. PVC, polyamide, polyolefin, polyethylene-terephthalates and composites containing at least one of these materials, if desired also aluminium foil.
One disadvantage of these known blister packs is that they are a combination of plastic and aluminium that have to be separated for disposal so that both the plastic waste and aluminium waste can be recycled.
The object of the present invention is to provide a lidding material made up of materials that are basically of the same kind, m particular of the same or similar group of thermoplastics as the base material, and features all or most of the positive properties of aluminium.